8.1 Introduction
After the Fukushima accident caused by the Great East Japan Earthquake, public
interest in the management of radioactive wastes and spent nuclear fuels has
increased. The Science Council of Japan recommends prioritizing research and
developments to reduce the radiological burden of high-level wastes by transmutation technology.
The Japan Atomic Energy Agency (JAEA) proceeded with R&D to reduce the
radiological hazard of high-level wastes by partitioning and transmutation (P-T)
technology [1]. In the framework of the J-PARC project, JAEA also promoted
constructing the Transmutation Experimental Facility (TEF) to study minor
actinide (MA) transmutation by both fast reactors and accelerator-driven systems
[2]. TEF is located at the end of the LINAC, which is also an important component
to be developed for future ADS, and shares the proton beam with other experimental facilities used for material sciences, life sciences, and high-energy nuclear
physics.
The TEF (Fig. 8.1) consists of two buildings, the Transmutation Physics Experimental Facility (TEF-P) [3] and the ADS Target Test Facility (TEF-T) [4]. Two
facilities are connected by the proton beam line with a low-power beam extraction
mechanism using a laser beam [5]. TEF-P is a facility with zero-power critical
assembly wherein a low-power proton beam is available to study the reactor physics
and the controllability of accelerator-driven systems (ADS). It also has availability
for measuring the reaction cross sections of MA and structural materials, for
example. TEF-T is planned as an irradiation test facility that can accept a maximum
400 MeV–250 kW proton beam to the lead-bismuth (Pb-Bi) spallation target. Using
these two facilities, the basic physical properties of a subcritical system and
engineering tests of a spallation target are to be studied.
R&Ds for important technologies required to build the facilities are also
performed, such as laser charge exchange technique to extract a very low power
proton beam for reactor physics experiments, a remote handling method to load
MA-bearing fuel into the critical assembly, and a spallation product removal
method especially for the polonium. The objectives and construction schedule of
the facilities, the latest design concept, and key technologies to construct TEF are
under way.
8.2 Outline of the Transmutation Experimental Facility
8.2.1 Outline of TEF-T
For the JAEA-proposed ADS, Pb-Bi is a primary candidate of coolant and spallation target. To solve technical difficulties for Pb-Bi utilization, construction of
TEF-T is planned to complete the data sets that are required for the design of ADS.
74
T. Sasa
After the Fukushima accident caused by the Great East Japan Earthquake, public
interest in the management of radioactive wastes and spent nuclear fuels has
increased. The Science Council of Japan recommends prioritizing research and
developments to reduce the radiological burden of high-level wastes by transmutation technology.
The Japan Atomic Energy Agency (JAEA) proceeded with R&D to reduce the
radiological hazard of high-level wastes by partitioning and transmutation (P-T)
technology [1]. In the framework of the J-PARC project, JAEA also promoted
constructing the Transmutation Experimental Facility (TEF) to study minor
actinide (MA) transmutation by both fast reactors and accelerator-driven systems
[2]. TEF is located at the end of the LINAC, which is also an important component
to be developed for future ADS, and shares the proton beam with other experimental facilities used for material sciences, life sciences, and high-energy nuclear
physics.
The TEF (Fig. 8.1) consists of two buildings, the Transmutation Physics Experimental Facility (TEF-P) [3] and the ADS Target Test Facility (TEF-T) [4]. Two
facilities are connected by the proton beam line with a low-power beam extraction
mechanism using a laser beam [5]. TEF-P is a facility with zero-power critical
assembly wherein a low-power proton beam is available to study the reactor physics
and the controllability of accelerator-driven systems (ADS). It also has availability
for measuring the reaction cross sections of MA and structural materials, for
example. TEF-T is planned as an irradiation test facility that can accept a maximum
400 MeV–250 kW proton beam to the lead-bismuth (Pb-Bi) spallation target. Using
these two facilities, the basic physical properties of a subcritical system and
engineering tests of a spallation target are to be studied.
R&Ds for important technologies required to build the facilities are also
performed, such as laser charge exchange technique to extract a very low power
proton beam for reactor physics experiments, a remote handling method to load
MA-bearing fuel into the critical assembly, and a spallation product removal
method especially for the polonium. The objectives and construction schedule of
the facilities, the latest design concept, and key technologies to construct TEF are
under way.
8.2 Outline of the Transmutation Experimental Facility
8.2.1 Outline of TEF-T
For the JAEA-proposed ADS, Pb-Bi is a primary candidate of coolant and spallation target. To solve technical difficulties for Pb-Bi utilization, construction of
TEF-T is planned to complete the data sets that are required for the design of ADS.
74
T. Sasa